German Published Patent Application No. 10 2005 020 380 describes a fuel-injection device having a sound-decoupling type of construction. The known fuel-injection device includes a fuel injector, a mounting bore for the fuel injector in a cylinder head and a fuel distributor having a connection piece. The fuel injector is placed in partially overlapping fashion into the connection piece. A joining body is disposed in such a way that it retains the fuel injector in a manner that the fuel injector and the joining body are inserted free of contact with respect to all surfaces or walls of the mounting bore of the cylinder head not running axially parallel to the fuel injector. In one possible form, the joining body is only a slotted snap ring. The snap ring engages in a tapered section of the inlet connection of the fuel injector. In the connection piece, a groove is provided in which the snap ring is snapped securely and firmly into place. To grasp below the fuel injector, the snap ring has a conical or curved spherical gripping surface. A hold-down device is clamped between the end face of the connection piece and a shoulder on the fuel injector.
The form of the fuel-injection device described in German Published Patent Application No. 10 2005 020 380 has the disadvantage that vibrations can be transmitted between the connection piece, the snap ring and the inlet connection. In particular, vibrations can be transmitted from the fuel injector to the connection piece.
Especially in the case of electromagnetic high-pressure injectors, which may be used in gasoline engines having direct injection, a noticeable and irritating contribution may be made to the overall noise of the engine, which may be described as valve ticking. Such valve ticking results from the rapid opening and closing of the fuel injector, during which the valve needle is moved with strong momentum into the respective end stops. The striking of the valve needle in the end stops leads to briefly acting, but very high contact forces which are transferred in the form of structure-borne noise and vibrations via a housing of the fuel injector to the cylinder head and to a fuel distributor rail. This results in strong noise generation at the cylinder head and at the fuel distributor rail.